The present invention relates to a radial arch building structure, and more particularly to a fortified to be as if monolithic radial arch structure that may be constructed of generally-available, relatively inexpensive, preferably wooden, and substantially uniform, components, capable of being mass-produced remotely from a use site, and to torn a larger, weight-bearing-capable, generally-tubular structure viewed as having a complete circle viewed in cross section, or a generally-curved such structure comprising anything less than a complete circle viewed in cross section.
The term monolithic is defined in the dictionary as, formed of a single large stone, and as applied to a building, being very large and characterless, and in particular, faceless (in the sense of being uniform). Therefore, the term “as if monolithic” is used herein to describe a structure with separate parts but which are combined and fastened together so as to be capable of functioning as an integral and larger whole structure, and to be capable, for example, of being moved as a whole (as a unitary piece of stone), as for example would be the case being lifted with a cable dangling from a crane or a helicopter and attached at a single point, or multiple points, near the top of the monolithic radial arch structure, and also so that the monolithic radial arch structure can stand on its own, support weight on top of it, and successfully resist substantial shifting forces, lateral forces, and shear forces, all without damage to, destruction of, or disassembly of, the structure.
Such as if monolithic structures may be advantageous, since they may be, for example, capable of construction of many varying sizes in a covered, air-conditioned, weather and climate-controlled, fabrication facility with necessary tools and components readily available, and then, though preferably made of wood, they may be easily lifted from an upper securetnent point, or points, and transported to the field where the structures may be successfully used.
There continue to be needed, and there will continue to be needed in the future, arch structures capable of use for the construction of subway tunnels, for hypertubes for above-ground transport, for inhabitable building structures, for greenhouse structures, arched trellis structures, shade and weather shelters, flotation structures, and for other useful objects and systems. In such applications, having an as if monolithic structure comprised of a plurality of fortified uniform parts would be advantageous, since the structure could be mass-produced in a remote warehouse, out of the elements, and easily transported to the use site.
Subway tunnels have been formed by a process wherein a tunnel is dug in the side of a hill, the tunnel being just large enough to accommodate building an arched structure within the tunnel to create a form for receiving reinforced concrete to be poured or pumped in the space between the tunnel walls and the form. Then, preferably once the poured concrete has hardened, the form would be removed and re-built, or otherwise used, in another section of the tunnel. For such operations, it may be advantageous to use a fortified to be as if monolithic semi-circular (in cross-section) wooden, steel, or aluminum, arch structure.
Regarding an above-ground hypertube, an acceptable method of constructing an above-ground hypertube would be to create a fully circular cross-section tube capable of being covered, such as sheeted, and for the creation of a vacuum environment within the hypertube capable of sustaining transport of a vehicle or person through the tube, either on rails, electromagnetic or otherwise, and while withstanding the vacuum forces tending to implode such a structure. For such operations, it would be advantageous to use a fortified to be as if monolithic fully-circular (in cross-section) arch-structure tubes.
Of course, arched structures are known generally, whether they have been created from stone, timber, steel, reinforced concrete, aluminum, or other building materials, and such have proven useful for creating tunnels, buildings, barracks, warehouses, shelters, arched-trellises, and other structures. But to date there has been lacking a monolithic-type such arch structure, preferably made of wood and capable of constructed remotely from generally uniformly-sized, and relatively-smaller, materials, likewise capable of being moved as a completed structure from the fabrication location to a field use location.
In U.S. Pat. No. 4,412,405 to Tucker, there is provided a radial arch structure constructed from relatively short and straight members or beams angularly related and forming chords of a generally curved, or circular, arc, which structure may have been erected by a minimum number of persons. While such may have been employed in the form of a roof, or roof supporting, structure mounted between a pair of walls to keep the arch structure from collapsing, such structures as disclosed in the '405 patent are not as if monolithic.
This is largely because the '405 patent radial arch structure has required intermediate midway-positioned notches in longitudinally-extending (stringer) members, as well as intermediate midway-positioned notches and end notches in transverse (arch) members, to help hold the arch structure of the '405 patent together against an anchoring point relative to a wall or foundation. Such application of notches and such need for anchoring have made the '405 patent not readily mobile and non-as-if-monolithic. Further, this need for notches has taught away from the use of fasteners and has weakened the members of the '405 patent structure, thus having weakened the resulting structure and having made it unsuitable for larger, heavier, and load bearing structures. This, in turn, has substantially limited the size and types of structures feasibly capable of being constructed in accordance with the '405 patent. Further, the notching and need for anchoring for such structures made according to the '405 patent have been complicated in the process of their construction, such that such structures have not been commercially or structurally feasible from an engineering standpoint.
Structures according to the '405 patent's teachings have therefore been limited in size so that they could not, for example, readily carry the load of a larger structure such as that required for building a subway tube, sections of a hypertube, flotation devices for floating housing, or a relocatable structure such as military barracks in the field. This has been because as larger materials have been sought for withstanding larger loads associated with these types of applications, the '405 patent structure has, per its terms, required increasingly large intermediate and end notches which have unduly weakened the structural integrity of the members. As such, engineering and permitting entities generally have not been readily willing to approve such structures for larger load bearing buildings and structures.
Further, the radial arch structure of the '405 patent has not employed intermediate fasteners between each of the members of the structure, and nor has it employed a post-tensioning type cable for holding the structure together. Thus, the arch structure of the '405 patent has required mounting or otherwise securing to fixed anchors on both sides of the arch (in the case of a barracks type building with sidewalls and a semi-circular cross-section root) to create sufficient integrity so that the arch would not have collapsed, so long as it has remained anchored. With such a structure, earthquake proofing has required the use of Simpson® brand ties comprising sometimes angled brackets fastened at component interfaces as known in the art. And, thus again, such an arch has been non-as-if-monolithic and not practical as a removable structure, especially without such ties, since it could not have survived easy-access uplift (as with a hook from a crane or helicopter attached at an upper portion of the structure) or other removal and relocation, without likely falling apart or otherwise collapsing. And thus, it would also be advantageous to have such an as if monolithic structure without the need for such ties.
Thus, there exists a need for simply-erected radial arch structures, preferably comprised of wood, but also able to be constructed of aluminum, steel, or other suitable material, that may span up to a generally complete cross-section circle, or generally having some degree less of an arched cross-section. Such radial arch structures may be temporary or permanent, and they would be preferably monolithic and capable of carrying, or withstanding, heavier loads and capable of spanning a required reasonable distance or space. Preferably, such structures would be capable of being constructed by a minimum number of persons without advanced knowledge of construction techniques or tools. Thus, for example, it would be advantageous for relatively unskilled individuals to be able to assemble temporary semi-circular cross-section radial arch buildings, made of wood, to shelter large numbers of persons or things, all from a plurality of largely uniform parts, and with the resulting structure being capable of being moved as if a monolithic structure by lifting as with a hook, or hooks, adjacent an upper portion of the structure. Further, there exists a need for such radial arch structures that are capable of being formed, preferably of wood, in a dome-shaped, or alternatively spherical-shaped, as if monolithic structure.
Regarding higher, or very high, load-bearing structures, there have been provided means of fortifying such, and there has been some reluctance to use wood, including pre-stressed wood components for such, because such components may be seen as more likely to break down over time, and thus have required updating of pre-stressing of such. See, e.g., U.S. Pat. No. 6,170,209 to Dagher et al., for Prestressing System For Wood Structures and Elements. Though the Dagher system is considered unlike that of the present disclosure in many respects, it may be considered instructive regarding building of more sturdy wooden structures in general.